Dissertations / Theses: 'Space time codes'

1

Karacayir, Murat. "Space-time Codes." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612028/index.pdf.

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The phenomenon of fading constitutes a fundamental problem in wireless communications. Researchers have proposed many methods to improve the reliability of communication over wireless channels in the presence of fading. Many studies on this topic have focused on diversity techniques. Transmit diversity is a common diversity type in which multiple antennas are employed at the transmitter. Space-time coding is a technique based on transmit diversity introduced by Tarokh et alii in 1998. In this thesis, various types of space-time codes are examined. Since they were originally introduced in the form of trellis codes, a major part is devoted to space-time trellis codes where the fundamental design criteria are established. Then, space-time block coding, which presents a different approach, is introduced and orthogonal spacetime block codes are analyzed in some detail. Lastly, rank codes from coding theory are studied and their relation to space-time coding are investigated.

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2

Pak, Anne On-Yi 1977. "Euclidean space codes as space-time block codes." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86722.

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Al-Ghadhban, Samir Naser. "Multi-layered Space Frequency Time Codes." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29498.

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This dissertation focuses on three major advances on multiple-input multiple-output (MIMO) systems. The first studies and compares decoding algorithms for multi-layered space time coded (MLSTC) systems. These are single user systems that combine spatial multiplexing and transmit diversity. Each layer consists of a space time code. The detection algorithms are based on multi-user detection theory. We consider joint, interference nulling and cancellation, and spatial sequence estimation algorithms. As part of joint detection algorithms, the sphere decoder is studied and its complexity is evaluated over MIMO channels. The second part contributes to the field of space frequency time (SFT) coding for MIMO-OFDM systems. It proposes a full spatial and frequency diversity codes at much lower number of trellis states. The third part proposes and compares uplink scheduling algorithms for multiuser systems with spatial multiplexing. Several scheduling criteria are examined and compared. The capacity and error rate study of MLSTBC reveals the performance of the detection algorithms and their advantage over other open loop MIMO schemes. The results show that the nulling and cancellation operations limit the diversity of the system to the first detected layer in serial algorithms. For parallel algorithms, the diversity of the system is dominated by the performance after parallel nulling. Theoretically, parallel cancellation should provide full receive diversity per layer but error propagations as a result of cancellation prevent the system from reaching this goal. However, parallel cancellation provides some gains but it doesn't increase the diversity. On the other hand, joint detection provides full receive diversity per layer. It could be practically implemented with sphere decoding which has a cubic complexity at high SNR. The results of the SFT coding show the superiority of the IQ-SFT codes over other codes at the same number of sates. The IQ-SFT codes achieve full spatial and frequency diversity at much lower number of trellis states compared to conventional codes. For V-BLAST scheduling, we propose V-BLAST capacity maximizing scheduler and we show that scheduling based on optimal MIMO capacity doesn't work well for V-BLAST. The results also show that maximum minimum singularvalue (MaxMinSV) scheduling performs very close to the V-BLAST capacity maximizing scheduler since it takes into account both the channel power and the orthogonality of the channel.
Ph. D.

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4

Acharya, Om Nath, and Sabin Upadhyaya. "Space Time Coding For Wireless Communication." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-19424.

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As the demand of high data rate is increasing, a lot of research is being conducted in the field of wireless communication. A well-known channel coding technique called Space-Time Coding has been implemented in the wireless Communication systems using multiple antennas to ensure the high speed communication as well as reliability by exploiting limited spectrum and maintaining the power. In this thesis, Space-Time Coding is discussed along with other related topics with special focus on Alamouti Space-Time Block Code. The Alamouti Codes show good performance in terms of bit error rate over Rayleigh fading channel. The performance of Altamonte’s code and MIMO capacity is evaluated by using MATLAB simulation.

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Panagos, Adam G., and Kurt Kosbar. "A METHOD FOR FINDING BETTER SPACE-TIME CODES FOR MIMO CHANNELS." International Foundation for Telemetering, 2005. http://hdl.handle.net/10150/604782.

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ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada
Multiple-input multiple output (MIMO) communication systems can have dramatically higher throughput than single-input, single-output systems. Unfortunately, it can be difficult to find the space-time codes these systems need to achieve their potential. Previously published results located good codes by minimizing the maximum correlation between transmitted signals. This paper shows how this min-max method may produce sub-optimal codes. A new method which sorts codes based on the union bound of pairwise error probabilities is presented. This new technique can identify superior MIMO codes, providing higher system throughput without increasing the transmitted power or bandwidth requirements.

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6

Gu, Yu. "Noncoherent communications using space-time trellis codes." Thesis, University of Canterbury. Electrical and Computer Engineering, 2008. http://hdl.handle.net/10092/1252.

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In the last decade much interest has been shown in space-time trellis codes (STTCs) since they can offer coding gain along with the ability to exploit the space and time diversity of MIMO channels. STTCs can be flexibly designed by trading off performance versus complexity. The work of Dayal [1] stated that if training symbols are used together with data symbols, then a space-time code can be viewed as a noncoherent code. The authors of [1] described the migration from coherent space-time codes to training assisted noncoherent space-time codes. This work focuses on the development of training assisted noncoherent STTCs, thus extending the concept of noncoherent training codes to STTCs. We investigate the intrinsic link between coherent and noncoherent demod- ulation. By analyzing noncoherent STTCs for up to four transmit antennas, we see that they have similar performance deterioration to noncoherently demodulated M-PSK using a single antenna. Various simulations have been done to confirm the analysis.

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Rouchy, Christophe. "Systematic Design of Space-Time Convolutional Codes." Thesis, University of California, Santa Cruz, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1554232.

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Space-time convolutional code (STCC) is a technique that combines transmit diversity and coding to improve reliability in wireless fading channels. In this proposal, we demonstrate a systematic design of multi-level quadrature amplitude modulation (M-QAM) STCCs utilizing quadrature phase shift keying (QPSK) STCC as component codes for any number of transmit antennas. Morever, a low complexity decoding algorithm is introduced, where the decoding complexity increases linearly by the number of transmit antennas. The approach is based on utilizing a group interference cancellation technique also known as combined array processing (CAP) technique.

Finally, our research topic will explore: with the current approach, a scalable STTC with better performance as compared to space- time block code (STBC) combined with multiple trellis coded modulation (MTCM) also known as STBC-MTCM; the design of low complexity decoder for STTC; the combination of our approach with multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM).

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Siwamogsatham, Siwaruk. "Improved space-time codes for wireless communications /." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486459267521456.

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Lamahewa, Tharaka Anuradha. "Space-time coding and space-time channel modelling for wireless communications /." View thesis entry in Australian Digital Theses Program, 2006. http://thesis.anu.edu.au/public/adt-ANU20070816.152647/index.html.

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Singhal, Rohit. "Multiple symbol decoding of differential space-time codes." Texas A&M University, 2003. http://hdl.handle.net/1969.1/344.

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Multiple-symbol detection of space-time differential codes (MS-STDC) decodes N consecutive space-time symbols using maximum likelihood (ML) sequence detection to gain in performance over the conventional differential detection scheme. However its computational complexity is exponential in N . A fast algorithm for implementing the MD-STDC in block-fading channels with complexity O(N 4) is developed. Its performance in both block-fading and symbol-by-symbol fading channels is demonstrated through simulations. Set partitioning in hierarchical trees (SPIHT) coupled with rate compatible punctured convolution code (RCPC) and cyclic redundancy check (CRC) is employed as a generalized multiple description source coder with robustness to channel errors. We propose a serial concatenation of the above with a differential space-time code (STDC) and invoke an iterative joint source channel decoding procedure for decoding differentially space-time coded multiple descriptions. Experiments show a gain of up to 5 dB in PSNR with four iterations for image transmission in the absence of channel state information (CSI) at the receiver. A serial concatenation of SPIHT + RCPC/CRC is also considered with space-time codes (STC) instead of STDC. Experiments show a gain of up to 7 dB with four iterations in the absence of CSI

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Pereira, Alvaro. "Space-time ring TCM codes on fading channels." Thesis, Staffordshire University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402455.

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Ali, Saajed. "Concatenation of Space-Time Block Codes with ConvolutionalCodes." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/9724.

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Multiple antennas help in combating the destructive effects of fading as well as improve the spectral efficiency of a communication system. Receive diversity techniques like maximal ratio receive combining have been popular means of introducing multiple antennas into communication systems. Space-time block codes present a way of introducing transmit diversity into the communication system with similar complexity and performance as maximal ratio receive combining. In this thesis we study the performance of space-time block codes in Rayleigh fading channel. In particular, the quasi-static assumption on the fading channel is removed to study how the space-time block coded system behaves in fast fading. In this context, the complexity versus performance trade-off for a space-time block coded receiver is studied. As a means to improve the performance of space-time block coded systems concatenation by convolutional codes is introduced. The improvement in the diversity order by the introduction of convolutional codes into the space-time block coded system is discussed. A general analytic expression for the error performance of a space-time block coded system is derived. This expression is utilized to obtain general expressions for the error performance of convolutionally concatenated space-time block coded systems utilizing both hard and soft decision decoding. Simulation results are presented and are compared with the analytical results.
Master of Science

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13

Wong, Wing Hin. "Nonuniform space-time codes for layered source coding." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000826.

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Niyomsataya, Terasan. "New unitary space-time codes with high diversity products." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26730.

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We propose new unitary space-time codes with high diversity products for multiple antenna wireless communications. These Hamiltonian and product constellations have full diversity, and can be used for any number of transmitter antennas and for any data rate. Hamiltonian constellations for-two transmitter antennas are based on Slepian's group codes. We construct Hamiltonian constellations for any M transmitter antennas by using a direct sum of 2 x 2 Hamiltonian matrices for M even, and a direct sum of 2 x 2 Hamiltonian matrices with the roots of unity for M odd. Product constellations are proposed using a product of a Hamiltonian constellation and a representation of cyclic group. We also present product constellations of two Hamiltonian constellations with diagonal blocks in different order for M odd. Many of our constellations outperform, and have higher diversity products, than the best known space-time constellation designs in the literature.

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15

Raad, Ibrahim Samir. "Study of turbo codes across space time spreading channel." School of Electrical, Computer and Telecommunications Engineering - Faculty of Informatics, 2004. http://ro.uow.edu.au/theses/269.

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This thesis deals with an application of turbo codes across Space Time Spreading Channel. This is done by undertaking a study into the extent to which these error correction codes can reduce the bit error rate across the space time spreading channel. Both the turbo codes and space time channel have been developed in Matlab�s Simulink. The thesis starts with an introduction to turbo codes which is presented on the basis of classical turbo codes introduced by Berrou et al in 1993 (Berrou et al., 1993). This is illustrated by some examples of their performance across the Additive White Gaussian Noise Channel (AWGN). Then a detailed description of the Space Time Spreading (STS) channel and the Universal Mobile Telecommunications Systems (UMTS) turbo codes. Using the UMTS turbo codes this thesis produces simulation results showing to what extent they reduce the bit error rate of the STS channel. A description of the system in Simulink and Matlab is presented. The simulation results show that UMTS turbo codes applied on the top of the STS channel can improve the bit error rate performance by approximately 5dB. This is done at the expense of increased complexity and reduced effective data rate.

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Liao, Huiyong. "Lattice based space-time block codes for MIMO system." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 155 p, 2007. http://proquest.umi.com/pqdweb?did=1251904861&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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Zhang, Zhi. "Error-rate evaluation and optimization for space-time codes." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39634218.

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Baghaie, Abchuyeh Marjan. "Multilevel Space-Time Trellis Codes for Rayleigh Fading Channels." Thesis, University of Canterbury. Electrical and Computer Engineering, 2008. http://hdl.handle.net/10092/2101.

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Demand for capacity in wireless communication systems has been rapidly growing world- wide. This has been driven by increasing data rate requirements of cellular mobile systems, and demand for wireless Internet and multimedia services. As the available radio spec- trum is limited, higher data rates can only be achieved by designing more efficient signaling techniques. In this thesis, we propose a new transmission scheme, which benefits from the advantages of conventional space-time trellis codes (CSTTCs) but does not have the disadvantages, especially for larger signal constellations. We achieve this by developing a new class of codes, called Multilevel Space-Time Trellis Codes (IMLSTTC). The new scheme provides a scalable and promising alternative to CSTTCs, by providing the system designer with the flexibility to choose any desired balance between code performance, complexity and throughput. The proposed scheme outperforms layered schemes at high SNRs, using a smaller number of antennas.

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19

Zhang, Zhi, and 張治. "Error-rate evaluation and optimization for space-time codes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39634218.

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Sengupta, Avik. "Redundant residue number system based space-time block codes." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/14111.

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Master of Science
Department of Electrical and Computer Engineering
Balasubramaniam Natarajan
Space-time coding (STC) schemes for Multiple Input Multiple Output (MIMO) systems have been an area of active research in the past decade. In this thesis, we propose a novel design of Space-Time Block Codes (STBCs) using Redundant Residue Number System (RRNS) codes, which are ideal for high data rate communication systems. Application of RRNS as a concatenated STC scheme to a MIMO wireless communication system is the main motivation for this work. We have optimized the link between residues and complex constellations by incorporating the “Direct Mapping” scheme, where residues are mapped directly to Gray coded constellations. Knowledge of apriori probabilities of residues is utilized to implement a probability based “Distance-Aware Direct Mapping” (DA) scheme, which uses a set-partitioning approach to map the most probable residues such that they are separated by the maximum possible distance. We have proposed an “Indirect Mapping” scheme, where we convert the residues back to bits before mapping them. We have also proposed an adaptive demapping scheme which utilizes the RRNS code structure to reduce the ML decoding complexity and improve the error performance. We quantify the upper bounds on codeword and bit error probabilities of both Systematic and Non-systematic RRNS-STBC and characterize the achievable coding and diversity gains assuming maximum likelihood decoding (MLD). Simulation results demonstrate that the DA Mapping scheme provides performance gain relative to a Gray coded direct mapping scheme. We show that Systematic RRNS-STBC codes provide superior performance compared to Nonsystematic RRNS-STBC, for the same code parameters, owing to more efficient binary to residue mapping. When compared to other concatenated STBC and Orthogonal STBC (OSTBC) schemes, the proposed system gives better performance at low SNRs.

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21

Gozali, Ran. "Space-Time Codes for High Data Rate Wireless Communications." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/27193.

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Space-time codes (STC) are a class of signaling techniques, offering coding and diversity gains along with improved spectral efficiency. These codes exploit both the spatial and the temporal diversity of the wireless link by combining the design of the error correction code, modulation scheme and array processing. STC are well suited for improving the downlink performance, which is the bottleneck in asymmetric applications such as downstream Internet. Three original contributions to the area of STC are presented in this dissertation. First, the development of analytic tools that determine the fundamental limits on the performance of STC in a variety of channel conditions. For trellis-type STC, transfer function based techniques are applied to derive performance bounds over Rayleigh, Rician and correlated fading environments. For block-type STC, an analytic framework that supports various complex orthogonal designs with arbitrary signal cardinalities and array configurations is developed. In the second part of the dissertation, the Virginia Tech Space-Time Advanced Radio (VT-STAR) is designed, introducing a multi-antenna hardware laboratory test bed, which facilitates characterization of the multiple-input multiple-output (MIMO) channel and validation of various space-time approaches. In the third part of the dissertation, two novel space-time architectures paired with iterative processing principles are proposed. The first extends the suitability of STC to outdoor wireless communications by employing iterative equalization/decoding for time dispersive channels and the second employs iterative interference cancellation/decoding to solve the error propagation problem of Bell-Labs Layered Space-Time Architecture (BLAST). Results show that remarkable energy and spectral efficiencies are achievable by combining concepts drawn from space-time coding, multiuser detection, array processing and iterative decoding.
Ph. D.

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22

Lin, Rui. "Hybrid ARQ Schemes for Non-orthogonal Space-time Block Codes." Thesis, University of Canterbury. Electrical and Computer Engineering, 2007. http://hdl.handle.net/10092/1183.

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Automatic Repeat-reQuest (ARQ) schemes are extensively used in communication systems and computer networks to achieve reliable transmission. Using space-time codes (STCs) with multiple input multiple output (MIMO) or multiple input single output (MISO) systems is an effective way to combat multipath fading, which is the most severe impairment for wireless communication systems. STCs are designed to use the rich scattering multipath environment provided by using multiple transmit antennas. The work done in this thesis focuses on the use of ARQ schemes with non-orthogonal space-time block codes (NOSTBCs) based on Reed Solomon codes. The truncated-selective ARQ (TS-ARQ) scheme is considered and three novel hybrid ARQ (HARQ) schemes are proposed. Simulation results reveal that, compared to using TS-ARQ with orthogonal space-time block codes (OSTBCs), using NOSTBCs with any of the three proposed HARQ schemes can provide significant gains in terms of dropped packet rate and spectral efficiency at the cost of increased decoding complexity. The performance can be further improved by using the water filling principle to adaptively allocate transmit power among transmit antennas.

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23

Sinnokrot, Mohanned Omar. "Space-time block codes with low maximum-likelihood decoding complexity." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31752.

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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Barry, John; Committee Co-Chair: Madisetti, Vijay; Committee Member: Andrew, Alfred; Committee Member: Li, Ye; Committee Member: Ma, Xiaoli; Committee Member: Stuber, Gordon. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Zhao, Zhihong. "Performance improvement of polarization diversity scheme with space-time codes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0027/MQ51518.pdf.

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Menon, Rekha. "Impact of Channel Estimation Errors on Space Time Trellis Codes." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/36490.

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Space Time Trellis Coding (STTC) is a unique technique that combines the use of multiple transmit antennas with channel coding. This scheme provides capacity benefits in fading channels, and helps in improving the data rate and reliability of wireless communication. STTC schemes have been primarily designed assuming perfect channel estimates to be available at the receiver. However, in practical wireless systems, this is never the case. The noisy wireless channel precludes an exact characterization of channel coefficients. Even near-perfect channel estimates can necessitate huge overhead in terms of processing or spectral efficiency. This practical concern motivates the study of the impact of channel estimation errors on the design and performance of STTC.

The design criteria for STTC are validated in the absence of perfect channel estimates at the receiver. Analytical results are presented that model the performance of STTC systems in the presence of channel estimation errors. Training based channel estimation schemes are the most popular choice for STTC systems. The amount of training however, increases with the number of transmit antennas used, the number of multi-path components in the channel and a decrease in the channel coherence time. This dependence is shown to decrease the performance gain obtained when increasing the number of transmit antennas in STTC systems, especially in channels with a large Doppler spread (low channel coherence time). In frequency selective channels, the training overhead associated with increasing the number of antennas can be so large that no benefit is shown to be obtained by using STTC.

The amount of performance degradation due to channel estimation errors is shown to be influenced by system parameters such as the specific STTC code employed and the number of transmit and receive antennas in the system in addition to the magnitude of the estimation error. Hence inappropriate choice of system parameters is shown to significantly alter the performance pattern of STTC.

The viability of STTC in practical wireless systems is thus addressed and it is shown that that channel estimation could offset benefits derived from this scheme.

Master of Science

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Oruç, Özgür Altınkaya Mustafa Aziz. "Differential and coherent detection schemes for space-time block codes/." [s.l.]: [s.n.], 2002. http://library.iyte.edu.tr/tezler/master/elektrikveelektronikmuh/T000133.pdf.

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Van, Wyk Daniel Jacobus. "Space-time turbo coding for CDMA mobile communications." Pretoria : [s.n.], 2000. http://upetd.up.ac.za/thesis/available/etd-01172007-112643/.

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28

Dayal, Pranav. "Algebraic space-time codes for multi-antenna channels and distributed codes for cooperative wireless communication." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/dissertations/fullcit/3178357.

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Baker, Dirk A. "Space-time block coding with imperfect channel estimates." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1843.

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Thesis (M.S.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains iv, 74 p. : ill. Includes abstract. Includes bibliographical references (p. 73-74).

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Bauch, Gerhard. ""Turbo-Entzerrung" und Sendeantennen-Diversity mit "Space-Time-Codes" im Mobilfunk /." Düsseldorf : VDI-Verl, 2001. http://www.gbv.de/dms/bs/toc/329404792.pdf.

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Chu, Alice Pin-Chen. "High-Rate Space-Time Block Codes in Frequency-Selective Fading Channels." Thesis, University of Canterbury. Electrical and Computer Engineering, 2012. http://hdl.handle.net/10092/10360.

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The growing popularity of wireless communications networks has resulted in greater bandwidth contention and therefore spectrally efficient transmission schemes are highly sought after by designers. Space-time block codes (STBCs) in multiple-input, multiple-output (MIMO) systems are able to increase channel capacity as well as reduce error rate. A general linear space-time structure known as linear dispersion codes (LDCs) can be designed to achieve high-data rates and has been researched extensively for flat fading channels. However, very little research has been done on frequency-selective fading channels. The combination of ISI, signal interference from other transmitters and noise at the receiver mean that maximum likelihood sequence estimation (MLSE) requires high computational complexity. Detection schemes that can mitigate the signal interference can significantly reduce the complexity and allow intersymbol interference (ISI) equalization to be performed by a Viterbi decoder. In this thesis, detection of LDCs on frequency-selective channels is investigated. Two predominant detection schemes are investigated, namely linear processing and zero forcing (ZF). Linear processing depends on code orthogonality and is only suited for short channels and small modulation schemes. ZF cancels interfering signals when a sufficient number of receive antennas is deployed. However, this number increases with the channel length. Channel decay profiles are investigated for high-rate LDCs to ameliorate this limitation. Performance improves when the equalizer assumes a shorter channel than the actual length provided the truncated taps carry only a small portion of the total channel power. The LDC is also extended to a multiuser scenario where two independent users cooperate over half-duplex frequency-selective channels to achieve cooperative gain. The cooperative scheme transmits over three successive block intervals. Linear and zero-forcing detection are considered.

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CHANG, CHING-YEN, and 張淨嚴. "Multilevel Product-Coded Space-Time Block Codes." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/p34e56.

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碩士
國立臺北科技大學
電機工程系
107
Nowadays, the communication system is required to have high performance, high stability and high reliability. In this thesis, we use space-time block codes in the wireless communication system. An expanded QPSK signal set is partitioned into five levels. Then, multilevel product codes are used as the component codes. Simulation results are performed to verify the error performance.

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Shamsi, Khouzani Mehrdad. "Linear space-time codes." 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=370929&T=F.

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Haung, Chang-Chih, and 黃彰智. "Multilevel Space-time Codes." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/65050920179400460539.

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碩士
國立中央大學
電機工程研究所
90
This thesis is aimed at space-time trellis coding, using multilevel coding technology to decrease complexity. Chapter 3 focuses on full diversity space-time codes, using a code in [4] to design a space-time block code which has three transmission antennas. We try to change signal labeling and calculate　determinant in order to research error performance and transform this structure to a type of space-time trellis codes. Try to find a design method to construct space-time trellis codes instead of delay diversity scheme. Chapter 4 focuses on non-full diversity space-time codes which increase transmission rate and reduction of observe error performance. We also compare with space-time trellis coding in order to obtain more insights and improve its error performance.

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Yeh, Jui-Hua, and 葉瑞驊. "Topics in Space-Time Codes." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/23565990957283594884.

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碩士
國立交通大學
電信工程系
89
Space-time (ST) codes introduce inter-dependence of transmitted coded symbols in both time and spatial domains to attain high coding gain while taking full advantage of the transmit diversity. Tarokh's space-time trellis coded (STTC) structure, assuming a flat fading environment and perfect channel state information on the part of the receiver, enjoys many advantages like the high bandwidth efficiency, full diversity gain, and easy hardware implementation, their coding advantages are not especially impressive. This thesis proposes two new ST coding schemes with improved coding gains and suggests a receiver structure that takes the selective multipath fading into account. We first examine a class of serial-concatenated ST coded schemes. The proposed serially-concatenated ST code consists of a nonrecursive convolutional code as the outer code and a recursive space-time trellis codes (RSTTC) as the inner codes with an interleaver placed in between them. Such an arrangement is based on the fact that a serially-concatenated turbo code should a nonrecursive outer code and a recursive inner code. The second ST coding scheme differs from earlier ST schemes in that continuous phase modulation (CPM) is used in conjunction with ST codes, resulting a continuous phase space-time coded modulation (CPSTC). The constant envelop property of the CPM waveforms can not only ease the linearity requirement of the transmitter power amplifier but also provide extra coding gain. The associated performance demonstrate that 3-4 dB gain is achievable. If we add an interleaver between the delay diversity encoder and the CPM encoder then an extra 4 dB decoding gain can be obtained by applying iterated decoding. Finally, we consider the effect of channel frequency selectivity on the receiver design. Although it has been shown that the same design criteria are still valid if the multipath fading channel can be modeled as an FIR filter, the optimal receiver structure is different from that for flat fading channels. As has been shown before, channel memory can be advantageous for a coded system. This is because one can model the channel effect as a nonbinary convolutional encoder so that the receiver can perform iterated decoding on such a concatenated coded system. Therefore, we place an interleaver and then a rate-1 recursive encoder between the output of a ST encoder and the modulator so that the resulting effect on the received waveform is equivalent to a concatenated coding system with a recursive inner code. We evaluate the associated system performance under three different conditions: (i) perfect channel state information is available, (ii) pilot-assisted channel estimate is used, (iii) only blind decision-feedback channel estimate is available. The appendix examines two typical pilot-assisted channel estimation methods, namely, one that uses a PN sequence and those that employ an adaptive method. When a PN pilot sequence is used, correlation seems to be the most effective non-adaptive approach for channel sounding while if adaptive approach is desirable the normalized least mean squared (NLMS) algorithm is an attractive alternative.

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36

Chou, Feng-Chih, and 周逢智. "Multilevel Space-Time Block Codes." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/30570619539849096824.

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碩士
中原大學
電機工程研究所
95
The multipath wireless channel suffers severe attenuation. The effective techniques to mitigate multipath fading are time and frequency diversity. In most situations, the wireless channel is slow varying and frequency non-selective. Hence, antenna diversity is a practical technique for reducing the effect of multipath fading. Multiple input multiple output wireless channels can introduce spatial diversity and increased information capacity. These results have motivated a new area in error correcting codes. Space-time codeing(STC) schemes combine the channel code design and the use of multiple transmit antennas. With combining Multi-level coding technique and set partition of space-time block code set, We will propose a novel design of space-time block codes. Using Multi-level coding technique can get lower complexity and the better performance.

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37

Tseng, Show-wei, and 曾紹維. "Differential Space-Time Trellis Codes." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/77058943152053521817.

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碩士
國立中央大學
通訊工程學系
102
Recently there is a new noncoherent trellis codes, called differential trellis coded modulation used in the different states differ in different coding and split by collection designed trellis codes, in order to achieve better error performance. In this thesis, this incoherent trellis extends to multiple antennas system called differential space-time trellis code, first we STBC as an example, the 8PSK, 32 group may make a collection of signal segmentation, then do the fence in the state 4,8,16 difference coding, and several different states from the trellis code to do the analysis, compared with the original uncoded modulation differential space-time, a larger minimum noncoherent distance, and obtained a computer program simulation results also show a better performance of its errors. In addition, we also use the super-orthogonal space-time trellis codes, and make the collection division and in different states do differ coding, depending on the distance analysis, we found differential quadrature empty super state in 4,8 differential space-time fence gate code and 8,16 state trellis codes when the same minimum noncoherent distance, and simulation results show that there is very close to the error performance.

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38

Chou, Hong Yu, and 周弘育. "RS-Concatenated Multilevel Space-Time Codes." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/xw2zyc.

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碩士
國立臺北科技大學
電機工程系研究所
98
Over past several years, transmit diversity has been studied extensively to provide error performance for wireless systems. A novel technique for constructing multilevel space-time code is proposed. For a given orthogonal space-time block code, several component codes are combined in conjunction with set partitioning of the multidimensional signal constellation according to the coding gain distance criterion. Then, the associated scheme is further concatenated with an outer Reed-Solomon code. Simulation results show that the concatenated scheme can achieve excellent error performance with low decoding complexity.

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39

Lee, Kuan-Yi, and 李冠儀. "Systematic Design of Space-Time Codes." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/94963496935057269977.

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碩士
國立中正大學
電機工程研究所
91
In this thesis, we examine the properties of modulation signal constellation and then make use of these properties. By taking advantage of the properties among the modulation points, we design the orthogonal space-time codes and the corresponding generator matrix to produce those orthogonal codes. From simulation, we discover the orthogonal space-time codes found in this thesis are the kernel of discrete time Fourier transformation. Based on the observation and signal design flow, we propose the two-stage configuration and the index matrix generator for the orthogonal space-time encoder. By this way, we can obtain the orthogonal space-time codes systematically.

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40

Chen, I.-Ting, and 陳羿廷. "Super-Orthogonal Multilevel Space-Time Codes." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/34874335206348527594.

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碩士
中原大學
電機工程研究所
96
In wireless communication environments, the reliability of received signals degrade seriously at the receiver because of the effects of fading channels and signals jamming by each other. In order to reduce the influence of fading channel that cause by signal transmission. Foschini,Gans and Telatar proved that multiple input multiple output can introduce spatial diversity and increase information capacity. These results have motivated a new area in error correcting codes. Space-Time Coding (STC) schemes combine the channel code design and the use of multiple transmit antennas. In order to get the better performance. By the design concept of multilevel coding, a multilevel space-time code is constructed. But also have drawbacks just like coding rate decreasing So, we propose a novel space-time trellis coding scheme by concatenating a simple convolutional code and an expanded set of multilevel space-time codes. The proposed scheme without losing coding rate but has good performance.

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41

Behera, T. "Space-time codes for wireless communication." Thesis, 2014. http://ethesis.nitrkl.ac.in/5960/1/E-127.pdf.

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With an increasing demand for high data rate, there has been a lot of research in the field of wireless communication. This paper deals with the fundamentals of space-time coding for wireless communication systems. A well-known technique known as Space]Time Coding has been adopted in the systems using multiple antennas for high speed and reliable communication. The basic idea of space-time coding deals with the designing of two-dimensional signal matrix that is to be transmitted over an interval of time from a number of transmitting antennas. High data rate and improved bit error performance can be achieved by exploiting diversity in the spatial dimensions by designing appropriate signal structure. Space-Time Block Coding is a MIMO transmit strategy which exploits transmit diversity and high reliability. We analyze the basic design structure of the space- time codes and summarize their relative performances.

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42

Li, Ssu-Hsien, and 李思賢. "Concatenation of Turbo Product Codes and Space Time Block Codes." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/42h364.

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碩士
中原大學
電機工程研究所
92
Abstract The multipath wireless channel suffers severe attenuation. The Effective techniques to mitigate multipath fading are time and frequency diversity. Foschini,Gans and Telatar proved that multiple input multiple output can introduce spatial diversity and increased information capacity. These results have motivated a new area in error correcting codes . Space-Time Coding (STC) schemes can combine the channel code design and the use of multiple transmit antennas . The Space Time Trellis Codes (STTC) proposed by Tarkoh combine the trellis coding with symbol mapping into multiple transmit antennas . The Coding scheme expansion is done in antenna space. The Turbo Codes proposed by Berrou have powerful error correcting abilities. It would be benefit to design turbo codes for multiple antenna systems. To design space-time turbo codes with maximum space diversity and outstanding performance is still an open question. The Turbo Codes exhibited a troublesome error floor. Besides, the MAP algorithm which performs maximum likelihood bit estimation has a very large computation complexity . Recently turbo product codes (TPC) have been proposed . It can proved the performance of turbo codes. It is expected that TPC for multiple antenna systems would be powerful coding schemes with maximum diversity gain and large coding gain.

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43

Suh, Junghoon. "Space-time codes concatenated with turbo codes over fading channels." 2004. http://etd.utk.edu/2004/SuhJunghoon.pdf.

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Thesis (Ph. D.)--University of Tennessee, Knoxville, 2004.
Title from title page screen (May 20, 2004). Thesis advisor: Mostofa K. Howlader. Document formatted into pages (xvi, 157 p. : ill. (some col.)). Vita. Includes bibliographical references (p. 145-156).

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44

Sharma, G. V. V. "Performance Analysis Of Space-Time Coded Multiuser Detectors." Thesis, 2004. https://etd.iisc.ac.in/handle/2005/1203.

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45

Sharma, G. V. V. "Performance Analysis Of Space-Time Coded Multiuser Detectors." Thesis, 2004. http://etd.iisc.ernet.in/handle/2005/1203.

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46

Li, Kun-Tai, and 李昆泰. "Design of Group-Theoretical Space-Time Codes." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/50410702430123994248.

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碩士
國立中正大學
電機工程研究所
93
Differential transmission schemes are well tailored for unknown channels between transmitters and receivers. In a space-time coded (STC) system, the diversity product of a signal constellation and the number of matrices in the constellation will influence system performance, decoder complexity and the overall transmission rate. To achieve a low error probability at high SNR’s, the signal constellation must have full diversity and the minimum diversity product must be as large as possible. On the other hand, the encoders of group-based space-time codes share an elegant mathematical structure with a simple formula for diversity products. This thesis focuses on the encoder design of unitary space-time codes by examining space-time codes based on Cayley transform, fixed-point-free (FPF) finite groups, and special symplectic group Sp(2).

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47

Chiou, Shian-Jiun, and 邱顯鈞. "Space-Time codes for Uneqaul Error Protection." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/79251116988964907463.

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碩士
中原大學
電子工程研究所
92
With the progress of science and society, the demands for wireless multimedia services increase rapidly. However, the signals transmitted over wireless channels usually experience serious distortion due to the corruption of multipath fading and thermal noise. Space-time codes, which combine both of the spatial and temporal diversities, have been shown to provide excellent performance against the fading effect. Coding techniques for unequal error protection (UEP), which can provide different protecting efforts with respect to different protection requirements, can make the best use of channel bandwidth in many practical applications. In this thesis, space-time codes are combined with UEP for channel coding of high-rate wireless multimedia communications. We study the UEP capabilities of space-time codes from an algebraic viewpoint. The performance analysis together with some design criteria of the UEP space-time codes are presented. We also propose several schemes for constructing the space-time codes of powerful UEP capabilities, based on which tables of good UEP codes with various rates and memories are given.

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48

Wu, Cheng-yu, and 吳承祐. "On space-time codes with multupath diversity." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/78436921376781702423.

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碩士
國立交通大學
電子工程系所
94
Space-Time coding is a coding technique to achieve the diversity gain of multiple antennas system. Two popular space-time codes, space-time block code (STBC) and space-time trellis code (STTC), are investigated in [1] and [2] for flat fading channels without intersymbol interference. In this thesis, we extend space-time coding to frequency selective channels. We combine space-time coding with MLSE (Maximum Likelihood Sequence Estimator) algorithms to handle the intersymbol interference and exploit the multipath diversity gain of frequency selective channels. Furthermore we propose a new space-time trellis coding process that combines the coding with the channel effect, and achieve diversity gain by joint decoding at the receiver. On the other hand, we also compare the proposed algorithm with some related algorithm. Finally, simulation results will be presented to verify the diversity order and the performance of the proposed coding scheme.

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49

Chow, William. "Concatenated space-time block codes and turbo codes with unstructured interference." 2004. http://hdl.handle.net/1828/452.

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The performance of space-time block codes in providing transmit diversity is severely degraded when strong localized interference is present. This problem is addressed by investigating a recently proposed coherent space-time block code decoding algorithm for unknown interference suppression. The algorithm assumes a Gaussian noise and interference approximation and is based on a cyclic-based maximum-likelihood estimation technique (CML). In this thesis, simulations are done applying CML in a coherent system with unstructured interference to validate previous work. An extension of these results is obtained by examining factors that affect CML performance and modifying CML for use in a noncoherent system. To improve bit error rate performance, a turbo code for channel coding was added to both systems. This addition required the development of reliability metrics for soft-information transfer between the space-time block code detector and the turbo code decoder. Significant coding gains exceeding 8dB at a bit error rate of are achieved for the turbo-coded system when compared to that of an uncoded system.

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50

Lee, Jia-Jhan, and 李佳展. "Design Scheme of Space-Time Block Codes Concatenated with Turbo Codes." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/65108082199099493675.

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碩士
中興大學
電機工程學系所
95
The wireless channel suffers severe attenuation caused by multipath fading. The effective technique to mitigate multipath fading is to use the time or frequency diversity. The communication system with multiple input multiple output can combat the channel attenuation by spatial diversity and increase the channel information capacity. The principle of space-time coding schemes is to combine the concept of channel coding design and multiple transmit antennas, which are then effectively applied to multipath wireless channel. Since the amount of data transfer of the modern digital or mobile communication is increasing, the reliability of the data transfer has become more and more important. Therefore, the error correction coding has played a very important role in wireless communication channel. The turbo code is one of the most popular error correction codes at present due to its good error correction ability. Besides, the turbo code is adopted in the 3G mobile communication standard. In this thesis, we present the application of several important concepts of wireless digital communications, i.e., serial concatenation, turbo coding, and temporal and antenna diversity . We combine the turbo code and the space-time block code and use the LogMAP algorithm to implement the soft in/soft out decoding algorithms of turbo code. Finally, we present our simulation results under different encoding scheme of the space time block code. Furthermore, we also present the comparison of the simulation result under different rate of space-time block codes but the same number of transmit antennas.

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Dissertations / Theses on the topic 'Space time codes'

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